A New Subtlety

For the American G.I., peacekeeping's paradox is plain. Shooting to kill--something a soldier has practiced since basic training--is the best thing he can do in combat. But it's the worst thing he can do on a peacekeeping mission because an itchy trigger finger can spark civilian casualties, renewed warfare and national embarrassment. Since the cold war, which Russian and U.S. troops spent pacing in their garrisons awaiting World War III, military prowess has become a more subtle discipline. But subtlety has never been the U.S. military's strong suit, and no other modern military mission is as vexing to the Pentagon as...